Identifying proteomic signatures in treatment-naĂŻve individuals newly diagnosed with inflammatory bowel disease (IBD) may provide insights into the underlying pathophysiological mechanisms of the dise Show more
Identifying proteomic signatures in treatment-naĂŻve individuals newly diagnosed with inflammatory bowel disease (IBD) may provide insights into the underlying pathophysiological mechanisms of the disease and aid in distinguishing Crohn's disease (CD) from ulcerative colitis (UC). In the discovery phase, label-free quantitative proteomics was performed to analyze proteomic profiles in serum extracellular vesicles (EVs), serum, urine, and intestinal tissue from 100 newly diagnosed IBD patients (50 CD and 50 UC), and 51 healthy controls (HC). Serum candidate biomarkers were validated using ELISA in a separate subset cohort (87 CD, 134 UC, and 99 HC), and immunohistochemistry was performed on biopsies from the discovery cohort to confirm findings. We identified 419 proteins in serum EVs, 468 in serum, 683 in urine, and 2603 in intestinal tissue. ELISA results showed lower levels of TTR and APOC3 and higher levels of ATRN in UC patients compared to HC. Similarly, CD patients showed lower TTR and higher ATRN levels compared to HC. Moreover, serum protein S10A9 was differentially upregulated in CD vs UC. Immunohistochemistry revealed increased PRDX4 and AZU1 expression in the ileum of CD patients, whereas AOFB expression was lower in the ileum of CD and in the left colon of both CD and UC compared to HC. This comprehensive proteomic study has identified a set of proteins differentially expressed in IBD, which may contribute to a better understanding of its mechanisms and hold promise as candidate biomarkers. Although these findings are preliminary, they warrant further investigation to evaluate their diagnostic and therapeutic relevance. Show less
Nonalcoholic fatty liver disease (NAFLD) is being increasingly recognized as a major cause of liver-related morbidity and mortality. Given the increasing prevalence of obesity in western countries, NA Show more
Nonalcoholic fatty liver disease (NAFLD) is being increasingly recognized as a major cause of liver-related morbidity and mortality. Given the increasing prevalence of obesity in western countries, NAFLD has become an important public health problem. The principal aim of this study was to find differences in protein expression between patients with NAFLD and healthy controls. Changes in protein expression of liver samples from controls, nonalcoholic steatosis, and nonalcoholic steatohepatitis (NASH) subjects were analyzed by two-dimensional differential in-gel electrophoresis (DIGE). With this proteomic technique, hundreds of proteins can be analyzed simultaneously and their relative abundance can be calculated. Proteins showing significant changes (ratio ≥ 1.5, p < 0.05) were identified by MALDI TOF/TOF mass spectrometry. Western blot of tissue homogenates was then used as a complementary method to validate protein expression changes observed by DIGE. With the aim to have a noninvasive approach to detect changes produced in NAFLD-affected liver, validated proteins were further tested in serum samples of different cohorts of patients. Following this approach, we identified two candidate markers CPS1 and GRP78 that were differentially expressed between control, steatosis, and NASH. This proteomics approach demonstrates that DIGE combined with MALDI TOF/TOF and Western blot analysis of tissue and serum samples is a useful approach to identify candidate markers associated with NAFLD. Show less